Can speakers sound worse during break-in period?


I purchased a NOS pr of speakers ( I’m not disclosing their name. Not interested in hearing from their haters) and was really liking them before I started to seriously break them in. It seems like after 24 hours they seem to have changed and sound worse, or not as good as they did. Are they just going through changes with some drivers opening up faster than the others? I know there are many components involved in this process and some might be a head of the others. I’m assuming that’s the case and when everything comes together they will sing.
hiendmmoe
It took many days of my Revel Studio 2 speakers to break in.  I had a dealer demo a broken in pair in my home and I loved them so I bought a pair.  I set up the new pair with the help of my dealer and they sounded horrible- not at all what I had heard days before with the broken in pair.  After about a day of constant playing they started to sound a little more like they did before but it took over a week of constant play for them to fully break in.
 I set up the new pair with the help of my dealer and they sounded horrible
Theres no way they could sound horrible as a result of not being broken in. Its more likely they remained sounding horrible but you just learned to live with it. When are you going to upgrade them if you haven't already?